Rename -Wswitch-enum-redundant-default to -Wswitch-redundant-default.

This is for consistency, since the flag is actually under -Wswitch now, rather
than -Wswitch-enum (since it's really valuable for the former and rather
orthogonal to the latter)

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@148680 91177308-0d34-0410-b5e6-96231b3b80d8
6 files changed